Re: DIG-L: Ammonia in Biomethanation !!!!!!

["OLEL" <olel@vsnl.net>]

Dear Ken C.

Thanks for the responce!!

We dont have much iron in the Water. And our reactors are built in R.C.C. . Our Reactor distribution System is made up of H.D.P.E. The only place where we have Steel is the the liquid/gas/solids seperators.70% of these are out of reach of oxygen. And During the operations we get a very high H2S concentration  , to the tune of 2% in Biogas !!

Would like to know more about your experience with Coffee Waste Digestor.  And what do you mean by  Sludge as black mud ??

Did you carry out any  chemical analysis??

Thanks again!!! 

----- Original Message -----

From: renertech

To: digestion@crest.org

Sent: Friday, December 07, 2001 2:16 PM

Subject: Re: DIG-L: Ammonia in Biomethanation !!!!!!

Dear Avadhut, 

                         it was very interesting to read of your experience with opening up a digester after 6 years.  I don't know about the ammonia, but I can explain why you wouldn't smell much sulphide.   When we opened up a coffee wastes  digester half of the sludge was a black mud.   This was because there was a lot of iron in our water supply, and a lot of steel pipe in the make up, and all the corrosion  had trapped the sulphide as iron sulphide sludge.  When the air gets at it,  it gives out a lot of heat and reverts to metalic iron and flowers of sulphur.  However that heat can give all sorts of queer smells.  It can cook your sludge very nicely.    Hope that helps.  Ken C.

    

----- Original Message -----

From: OLEL

To: digestion@crest.org

Sent: Friday, December 07, 2001 6:00 PM

Subject: DIG-L: Ammonia in Biomethanation !!!!!!

I operate an anaerobic UASB system for the treatment of 700m3/day Cane molasses based Distillery Spentwash.

This plant has been in operation for the last 6 years.One of the UASB ractors was recently opened for the repairs of the feed distribution Network. Besides many interesting findings , one puzzling observation was that, throughout the period when the Anaerobic Biomass was being removed from the reactor(i. e. for about 3  weeks) , a very strong odour of Ammonia was persistent in the reactor.  Actually H2S smell was expected as the Spentwash contains high concentrations of sulfates and the Anaerobic Biomass contains Sulfate Reducing Bacteria. But No H2S smell was encountered.

 

Can somebody please throw some light on the possible reasons for the presence of this strong Ammonia smell ??

 

P.S. 1.No external Nitrogen was being added as the TKN  concentration in the distillery spentwash is in the range of 1000 to 1500 mg/L. 2. Moderate quantities of yeast may have accumulated in the reactor(Source: Distillery Spentwash).

 

Thanks.,

 

Avadhut Bapat